From: Michael Anthony Knyszek <mknyszek@google.com>
Date: Mon, 20 May 2024 20:18:02 +0000 (+0000)
Subject: runtime: correctly account for allocated objects in allocfree trace
X-Git-Tag: go1.23rc1~207
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=197101a84a563ee8fb6ac58bb91ab2de49f0cbce;p=gostls13.git

runtime: correctly account for allocated objects in allocfree trace

The current implementation doesn't handle s.freeindex at all, which
means it'll skip a whole bunch of recently-made allocations, because the
span may have not been swept yet.

Change-Id: I8c5e360f5927ffe7e9abb448b352a59875e31b02
Reviewed-on: https://go-review.googlesource.com/c/go/+/586996
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
---

diff --git a/src/runtime/traceallocfree.go b/src/runtime/traceallocfree.go
index e1190394ed..3067e16670 100644
--- a/src/runtime/traceallocfree.go
+++ b/src/runtime/traceallocfree.go
@@ -45,11 +45,10 @@ func traceSnapshotMemory() {
 		// Find all allocated objects.
 		abits := s.allocBitsForIndex(0)
 		for i := uintptr(0); i < uintptr(s.nelems); i++ {
-			if !abits.isMarked() {
-				continue
+			if abits.index < uintptr(s.freeindex) || abits.isMarked() {
+				x := s.base() + i*s.elemsize
+				trace.HeapObjectExists(x, s.typePointersOfUnchecked(x).typ)
 			}
-			x := s.base() + i*s.elemsize
-			trace.HeapObjectExists(x, s.typePointersOfUnchecked(x).typ)
 			abits.advance()
 		}
 	}